Racetrack memory is a type of non-volatile memory that utilizes magnetic domains, which are regions of uniform electron spin, distributed along a magnetic wire where each domain can store a bit of data. Racetrack memory can potentially provide data transfer speeds that exceed the data transfer rates in hard disk drives (HDDs), solid-state drives (SDDs), and even rapid access memory (RAM) and data storage densities greater than HDDs and SDDs at reduced costs. However, the development of racetrack memory has been hindered by the sensitivity of magnetic domains to defects in the magnetic wire, which can lead to substantial reductions in data transfer speeds.
To overcome the limitations imposed by magnetic domains in racetrack memory, magnetic skyrmions, which are small particle-like domains with a reversed magnetization relative to the bulk magnetization state of a magnetic material, can instead be used to store bits of data. Magnetic skyrmions are insensitive to material defects and can be moved at high speeds to facilitate fast data transfer rates. However, magnetic skyrmions have conventionally been generated using thermal mechanisms, resulting in a random generation of skyrmions in a material over time. This is of limited use for memory devices where bits of data should be generated at known locations in a deterministic manner.